Wheel structure

ABSTRACT

A wheel which comprises a hub having an axle receiving aperture, a first portion extending circumferentially about the hub, a second portion extending circumferentially about the first portion, the second portion having a hardness less than the hardness of the first portion, and the second portion forming at least a major percentage of the surface contacting area. The wheel is suitable for use on trolleys and the like wherein it is desirable to have a relatively soft portion when the trolley is stationary to thereby provide stability while, at the same time, providing an easy rolling capability.

FIELD OF THE INVENTION

The present invention relates to a wheel structure and moreparticularly, relates to a composite wheel structure.

BACKGROUND OF THE INVENTION

The use of composite wheels wherein there are provided two differentmaterials forming the same wheel, each for a desired end, is known inthe art. Primarily such wheels have been used for inline skates whereina harder surface is formed on the center of the blade wherein most ofthe skating motion occurs while a somewhat softer material is providedabout the periphery thereof.

In a number of uses, it is desirable for a wheeled item to be relativelyeasy to move while, when stopping, providing stability. Thus, one couldutilize such a structure on various types of trolleys and the likewherein it would be desirable to have a relatively soft portion when thetrolley is stationary and at the same time, providing an easy rollingcapability.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a composite wheelwhich has a combination of properties achieved by using materials havingdifferent hardnesses in a composite structure.

According to the present invention, there is provided a wheel comprisinga hub having an axle receiving aperture, a first portion extendingcircumferentially about the hub, the first portion having a firsthardness, a second portion extending circumferentially about the firstportion, the second portion having a second hardness, the second portionforming at least a major percentage of a surface contacting area, thearrangement being such that the second hardness is less than the firsthardness.

In a further aspect of the present invention, there is provided animprovement in a wheel having a central hub, the improvement comprisinga hub having an axle receiving aperture, a first portion extendingcircumferentially about the hub, the first portion having a firsthardness, a second portion extending circumferentially about the firstportion, the second portion having a second hardness, the second portionforming at least a major percentage of a surface contacting area, andthe arrangement being such that the second hardness is less than thefirst hardness.

The wheel will include a central hub which will have an axle receivingaperture extending therethrough as is well known in the art. The hub maybe formed of any suitable material including hard plastic materialsand/or metallic materials such as aluminum, steel, and alloys thereof.

In a preferred embodiment, the axle has a portion forming a bushingsurface although any conventional bearing and/or bushing structure maybe utilized depending on the final use of the wheel.

In one particularly preferred embodiment, the hub is formed of an innersegment and an outer segment with a central vertical flange extendingtherebetween. In other words, the hub will have a cross sectionalH-shaped configuration.

A first portion extends circumferentially about the hub and isinterlocked therewith. To this end, there may be provided grooves and/orrecesses adapted to receive retaining portions of the first portion.

Extending circumferentially about the first portion is a second portionwhich forms a primary substrate contacting surface of the wheel. Inother words, the second portion is located centrally of the outersurface of the wheel and constitutes at least 50% of the contactingsurface thereof.

The second portion is of a softer material than the first portion andtherefore has a lower hardness. It may conveniently be formed of amaterial such as polyurethane.

In the preferred embodiment, the first portion has a hardness of atleast 70 D while the second portion has a hardness of between 80 A and87 A.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the invention, reference will be made tothe accompanying drawings illustrating an embodiment thereof, in which:

FIG. 1 is a perspective view of a wheel according to the presentinvention;

FIG. 2 is a side elevation al view thereof;

FIG. 3 is a cross sectional view taken along the lines 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along the lines 4-4 of FIG. 3; and

FIG. 5 is a perspective cut-away view of the wheel structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in greater detail and by reference charactersthereto, there is illustrated in FIG. 1 a wheel which is generallydesignated by reference numeral 10.

Wheel 10, as may be best seen in cross section in FIG. 3, has a hubforming member generally designated by reference numeral 12. Hub 12 hasa first inner segment 15 on which there is provided a bushing portion14. Extending outwardly from inner segment 15 is a vertical centralflange 16 and which terminates in an outer segment 18.

Hub 12 also includes a first portion 20 which extends circumferentiallyoutwardly from outer segment 18 and which has sidewalls 22, 24 which arearcuate and meet at a circumferential wall 26. Outer segment 18 has aplurality of recesses therein including a first sidewall recess 28 and asecond sidewall recess 30. There is also a top wall recess 32.

As may be seen in FIGS. 3 and 5, a plurality of channels 34 extendthrough first portion 20 from sidewall 22 through sidewall 24.

Mounted on top of first portion 20 is a second portion which isgenerally designated by reference numeral 36 and which extendscircumferentially along circumferential wall 26 of first portion 20. Asmay clearly be seen in FIG. 3, second portion 36 has an outer wall 38which is arcuate in configuration. Outer wall 38 forms at least a majorportion of the substrate contacting surface. As will be appreciated, thesizing and relationship of second portion 36 will determine the amountof substrate contacting surface that it forms.

It will be understood that the above described embodiment is forpurposes of illustration only and that changes and modifications may bemade thereto without departing from the spirit and scope of theinvention.

1. A wheel comprising: a hub having an axle receiving aperture; a firstportion extending circumferentially about said hub, said first portionhaving a first hardness; a second portion extending circumferentiallyabout said first portion, said second portion having a second hardness,said second portion forming at least a major percentage of a surfacecontacting area; and the arrangement being such that said secondhardness is less than said first hardness.
 2. The wheel of claim 1wherein said first portion has a hardness of at least 70 D.
 3. The wheelof claim 2 wherein said second portion has a hardness of between 80 Aand 87 A.
 4. The wheel of claim 3 wherein said hub is formed of ametallic material.
 5. The wheel of claim 4 wherein said metallicmaterial is aluminum.
 6. The wheel of claim 4 wherein said first portionis formed of a plastic material.
 7. The wheel of claim 6 wherein saidsecond portion is formed of a polyurethane material.
 8. In a vehiclehaving wheels thereon, the improvement wherein at least one of saidwheels comprises: a hub having an axle receiving aperture; a firstportion extending circumferentially about said hub, said first portionhaving a first hardness; a second portion extending circumferentiallyabout said first portion, said second portion having a second hardness,said second portion forming at least a major percentage of a surfacecontacting area; and the arrangement being such that said secondhardness is less than said first hardness.